- Apologies for the mistakes in the scaling of the marks for CW5
(the second part of the cipher challenge). You should multiply the
marks sent to you by 5/4 to get the correct mark. The marks are still
a bit low, due to everyone going for the same ciphers, but since the
marks for the first half of the cipher challenge were correspondingly
high, the second examiner and I felt that on average the marks are reasonable.
- The marks for the cipher challenge are now available.
Marks for the encryptions are generally good (average above 80),
and I hope to get individual feedback to you tomorrow.
The numbers of solutions received to each cipher was as follows:
Number of solutions
- The ciphers which were broken this year are numbers
4, 5, 11, 24, 35, 37, 40, 43, 45, 51, 53, 55, 59, 61, 76, 78, 83, 84, 91, 93, 97 and 98.
- Assignment 8 is now available from the link below.
- Cipher challenge web page is now available
- Tuesday 19th February, 10.45 am. I am putting the finishing touches to the cipher challenge web page,
and will put the link here shortly. I have changed the rules this year,
so that there is no great advantage to starting work on the ciphers
- Cipher challenge: I have managed to process all the ciphers (L-Z) sent to me,
with two exceptions: Wong HC still needs to send me the full message
in shorter lines (see email). I have received nothing at all from Tran K or Zhang L:
this is your last chance to send something in.
- Reminder: NO lectures in Reading Week: 18th/19th February.
- Note that the Cipher Challenge consists of two parts: part 1 is encryption,
which counts 7.5% overall. Part 2 is decryption, which also counts 7.5%. The precise
marking scheme for part 2 will be decided once I have assessed the difficulty of
the ciphers submitted.
- Marked work and solutions can be collected in the tutorials. Any work which
is not collected will be deposited in the cabinet in the School Office in the
- The Tuesday tutorial has been moved from Eng 324 to Eng 325. Or possibly not.
- Web pages in preparation. For back-up
here is a link to
last year's web-pages.
Course descriptions and course information
This web-page and the notes etc. for the course closely follow
Peter Cameron's originals which he has very kindly allowed me to use.
His pages may still be accessible
The first ELEVEN instalments of the notes have been revised (very slightly) for 2008.
Instalment 12, which will not be lectured this year, is the 2006 version.
2: Substitution ciphers
3: Stream ciphers
4: Stream ciphers, continued
5: Stream ciphers, concluded
6: Public-key cryptography
7: Public-key cryptography: RSA
8: Public-key cryptography: Primes and
9: Public-key cryptography: El-Gamal
10: Public-key cryptography: Other ciphers
11: Secret sharing and other matters
12: Quantum effects; bibliography
Other course material
is the worked example of breaking a substitution cipher, done in Lecture 3.
The recommended book for reading before taking the course is Simon
The Code Book; the recommended course text is
Douglas Stinson's Cryptography: theory and practice (unfortunately, Paul Garrett's
Making, Breaking Codes is out of print). (See below for bibliographical details.)
is the list of ASCII 7-bit codes, and here are
the International Telegraph Codes.
are three samples of random text matching
the letter, digram and trigram frequencies in a piece of English text
(Lewis Carrol's Alice's Adventures in Wonderland).
"FISH and I" by W. T. Tutte (one of the Bletchley Park codebreakers).
- Here is the
College Historical Cryptography website.
- Here is a
of Maple lessons on topics in cryptography from Adept Scientific, which
be downloaded free of charge.
are some lecture notes by Peter Cameron on computational complexity.
John Preskill's Caltech notes on quantum computing.
is Sir Arthur Conan Doyle's "The Adventure of the Dancing Men"
- Here is Edgar Allan Poe's "The Gold-Bug" .
- Henry Beker and Fred Piper, Cipher Systems: The
Protection of Communications, Northwood Books, London, 1982.
- Robert Churchhouse, Codes and Ciphers: Julius Caesar,
the Enigma, and the Internet, Cambridge University Press,
- Paul Garrett, Making, Breaking Codes: An Introduction to
Cryptology, Prentice-Hall, Upper Saddle River, 2001.
- Simon Singh, The Code Book: The Secret History of Codes
and Code-Breaking, Fourth Estate, London, 1999.
- Douglas R. Stinson, Cryptography: Theory and Practice
(2nd edition), Chapman & Hall/CRC, Boca Raton, 2002.
- John Talbot and Dominic Welsh, Complexity and cryptography: An introduction,
Cambridge University Press, Cambridge, 2006.
- Dominic Welsh, Codes and Cryptography, Oxford
University Press, Oxford, 1988.
- Susan Loepp and William K. Wootters,
Protecting information: from classical error correction to
quantum cryptography, Cambridge University Press, 2006.
- Helen Fouché Gaines, Cryptanalysis: A Study of
Ciphers and their Solution, Dover Publ. (reprint), New York, 1956.
- F. H. Hinsley and Alan Stripp (eds.), Code Breakers: The
Inside Story of Bletchley Park, Oxford University Press, Oxford,
- Andrew Hodges, Alan Turing: The Enigma, Vintage,
- Leo Marks, Between Silk and Cyanide: The Story of SOE's
Code War, HarperCollins, London, 1998.
- Doron Swade, The Cogwheel Brain: Charles Babbage and the
Quest to Build the First Computer, Little, Brown & Co., London,
- Gordon Welchman, The Hut Six Story: Breaking the Enigma
Codes, M & M Baldwin, Cleobury Mortimer, 1998.
- Peter Wright, Spycatcher: The Candid Autobiography of a
Senior Intelligence Officer, Stoddart Publ. Co., Toronto, 1987.
- Sir Arthur Conan Doyle, The Adventure of the Dancing Men, in
The Complete Sherlock Holmes, Penguin (reprint), London,
- Edgar Allan Poe, The Gold-Bug, in Complete Tales and
Poems, Castle Books, Edison, NJ, 1985.
- Dorothy L. Sayers, Have His Carcase, Victor
Gollancz, London, 1932.
- Related topics:
- Richard Feynman, The Character of Physical Law, BBC
publications, London, 1965.
- M. R. Garey and D. S. Johnson, Computers and
Intractability: A Guide to the Theory of NP-Completeness, Freeman,
San Francisco, 1979.
- Ray Hill, A First Course in Coding Theory, Oxford
University Press, Oxford, 1986.
- Michael A. Nielsen and Isaac L. Chuang, Quantum
Information and Quantum Computation, Cambridge University Press,
- G. Mander (ed.), wot txters hav bin w8ing 4,
Michael O'Mara Books, London, 2000.
- Georges Perec (translated by Gilbert Adair), A Void,
Harvill Press, 1994.
- Ernest Vincent Wright, Gadsby, Wetzel Publishing
Co., Los Angeles, 1931.
Robert A. Wilson
(based on Peter Cameron's original page)
Created 5 January 2005
Updated 22 May 2008